Palisade

"An improvised wall made of logs and dirt. It blocks the line of sight."

A palisade blocks a soldier's line of sight. Your men can't see from behind it, and the Germans can't see through it. Note that it also blocks bullets, and is destructible. Good for hiding important units behind.

Also good if you enjoy watching CQC, as both sides may not realize the enemy is right next to them until they're too close for comfort. Enemy engineers are thing to watch out in this tactic.

Warning: The price of a palisade is bugged. The in-game description says building it costs 3 TPs but if you buy a palisade only 2 TPs are deducted.

Tips

The palisade performs a similar task to the Pillbox, which is keeping key soldiers out of harm's way while blocking their view of the battlefield. It costs less than the pillbox, making it a decent early-game alternative. However, unlike the pillbox, soldiers cannot enter it and it is destructible.

You can move your troops from behind the palisade, then back. This is ideal for taking a shot, then taking cover from the resulting enemy fire.

Rocks have the same effect as palisades, if one is in the right spot, you might not have to spend TPs on a palisade.

If your squad does not possess enough firepower to kill a PAK-38, it may be better to put a tank behind a palisade rather than let it fight it out.